diff --git a/src/drivers/net/3c515.c b/src/drivers/net/3c515.c
index 0aa68b1a..1591e061 100644
--- a/src/drivers/net/3c515.c
+++ b/src/drivers/net/3c515.c
@@ -389,7 +389,7 @@ static void t515_reset(struct nic *nic)
 		outb(PKT_BUF_SZ >> 8, nic->ioaddr + TxFreeThreshold);	/* Room for a packet. */
 		/* Clear the Tx ring. */
 		for (i = 0; i < TX_RING_SIZE; i++)
-			vp->tx_skbuff[i] = 0;
+			vp->tx_skbuff[i] = NULL;
 		outl(0, nic->ioaddr + DownListPtr);
 	}
 	/* Set receiver mode: presumably accept b-case and phys addr only. */
diff --git a/src/drivers/net/3c595.c b/src/drivers/net/3c595.c
index 1aa8ed64..2338c54b 100644
--- a/src/drivers/net/3c595.c
+++ b/src/drivers/net/3c595.c
@@ -399,7 +399,7 @@ vxsetlink(void)
 
     i = vx_connector;       /* default in EEPROM */
     reason = "default";
-    warning = 0;
+    warning = NULL;
 
     if ((vx_connectors & conn_tab[vx_connector].bit) == 0) {
         warning = "strange connector type in EEPROM.";
@@ -407,7 +407,7 @@ vxsetlink(void)
         i = CONNECTOR_UTP;
     }
 
-        if (warning != 0) {
+        if (warning) {
             printf("warning: %s\n", warning);
         }
         printf("selected %s. (%s)\n", conn_tab[i].name, reason);
diff --git a/src/drivers/net/bnx2.c b/src/drivers/net/bnx2.c
index a986bdef..4ebcc52a 100644
--- a/src/drivers/net/bnx2.c
+++ b/src/drivers/net/bnx2.c
@@ -2617,9 +2617,6 @@ bnx2_probe(struct nic *nic, struct pci_device *pdev)
 	struct bnx2 *bp = &bnx2;
 	int i, rc;
 
-	if (pdev == 0)
-		return 0;
-
 	memset(bp, 0, sizeof(*bp));
 
 	rc = bnx2_init_board(pdev, nic);
diff --git a/src/drivers/net/etherfabric.c b/src/drivers/net/etherfabric.c
index 6036d321..5e0efb1e 100644
--- a/src/drivers/net/etherfabric.c
+++ b/src/drivers/net/etherfabric.c
@@ -3798,7 +3798,8 @@ falcon_clear_interrupts ( struct efab_nic *efab )
 	}
 	else {
 		/* write to the INT_ACK register */
-		falcon_writel ( efab, 0, FCN_INT_ACK_KER_REG_A1 );
+		EFAB_ZERO_DWORD ( reg );
+		falcon_writel ( efab, &reg, FCN_INT_ACK_KER_REG_A1 );
 		mb();
 		falcon_readl ( efab, &reg,
 			       WORK_AROUND_BROKEN_PCI_READS_REG_KER_A1 );
diff --git a/src/drivers/net/ns8390.c b/src/drivers/net/ns8390.c
index a30f9361..0ffc6216 100644
--- a/src/drivers/net/ns8390.c
+++ b/src/drivers/net/ns8390.c
@@ -895,7 +895,7 @@ static int eth_probe (struct dev *dev, unsigned short *probe_addrs __unused)
 #endif
 			0 };
 		/* if no addresses supplied, fall back on defaults */
-		if (probe_addrs == 0 || probe_addrs[0] == 0)
+		if (probe_addrs == NULL || probe_addrs[0] == 0)
 			probe_addrs = base;
 		eth_bmem = 0;		/* No shared memory */
 		for (idx = 0; (eth_nic_base = probe_addrs[idx]) != 0; ++idx) {
diff --git a/src/drivers/net/prism2.c b/src/drivers/net/prism2.c
index ad388074..ab974264 100644
--- a/src/drivers/net/prism2.c
+++ b/src/drivers/net/prism2.c
@@ -130,9 +130,7 @@ typedef struct hfa384x
 } hfa384x_t;
 
 /* The global instance of the hardware (i.e. where we store iobase and membase, in the absence of anywhere better to put them */
-static hfa384x_t hw_global = {
-  0, 0, 0, 0, 0, 0, 0, {0,0,0,0,0,0}
-};
+static hfa384x_t hw_global;
 
 /*
  * 802.11 headers in addition to those in hfa384x_tx_frame_t (LLC and SNAP)
diff --git a/src/drivers/net/sis900.c b/src/drivers/net/sis900.c
index 75e9ef96..72451567 100644
--- a/src/drivers/net/sis900.c
+++ b/src/drivers/net/sis900.c
@@ -111,7 +111,7 @@ static struct mii_chip_info {
 //  {"NS 83851 PHY",0x2000, 0x5C20, MIX },
     {"RTL 8201 10/100Mbps Phyceiver"   , 0x0000, 0x8200,rtl8201_read_mode},
     {"VIA 6103 10/100Mbps Phyceiver", 0x0101, 0x8f20,vt6103_read_mode},
-    {0,0,0,0}
+    {NULL,0,0,NULL}
 };
 
 static struct mii_phy {
diff --git a/src/drivers/net/tlan.c b/src/drivers/net/tlan.c
index 74398df4..7742f6d8 100644
--- a/src/drivers/net/tlan.c
+++ b/src/drivers/net/tlan.c
@@ -94,7 +94,7 @@ static void TLan_MiiWriteReg(struct nic *nic __unused, u16, u16, u16);
 
 static const char *media[] = {
 	"10BaseT-HD ", "10BaseT-FD ", "100baseTx-HD ",
-	"100baseTx-FD", "100baseT4", 0
+	"100baseTx-FD", "100baseT4", NULL
 };
 
 /* This much match tlan_pci_tbl[]!  */
@@ -164,7 +164,7 @@ static const struct pci_id_info tlan_pci_tbl[] = {
 	{"Compaq NetFlex-3/E", 0,	/* EISA card */
 	 {0, 0, 0, 0, 0, 0},
 	 TLAN_ADAPTER_ACTIVITY_LED, 0x83},
-	{0, 0,
+	{NULL, 0,
 	 {0, 0, 0, 0, 0, 0},
 	 0, 0},
 };
diff --git a/src/drivers/net/tulip.c b/src/drivers/net/tulip.c
index 7a23b7e9..e4e6ffa8 100644
--- a/src/drivers/net/tulip.c
+++ b/src/drivers/net/tulip.c
@@ -228,7 +228,7 @@ static const struct pci_id_info pci_id_tbl[] = {
       TULIP_IOTYPE, TULIP_SIZE, COMET },
     { "SG Thomson STE10/100A", { 0x2774104a, 0xffffffff, 0, 0, 0, 0 },
       TULIP_IOTYPE, 256, COMET },	/*Ramesh Chander*/
-    { 0, { 0, 0, 0, 0, 0, 0 }, 0, 0, 0 },
+    { NULL, { 0, 0, 0, 0, 0, 0 }, 0, 0, 0 },
 };
 
 enum tbl_flag {
@@ -264,7 +264,7 @@ static struct tulip_chip_table {
     { "Xircom tulip work-alike", HAS_MII | HAS_MEDIA_TABLE | ALWAYS_CHECK_MII 
       | HAS_PWRDWN | HAS_NWAY },
     { "SGThomson STE10/100A", HAS_MII | MC_HASH_ONLY },	/*Ramesh Chander*/   
-    { 0, 0 },
+    { NULL, 0 },
 };
 
 /* A full-duplex map for media types. */
@@ -475,7 +475,7 @@ static struct fixups {
                                     0x1B03, 0x006D, /* 100baseTx, CSR12 0x1B */
                                     0x1B05, 0x006D, /* 100baseTx-FD CSR12 0x1B */
     }},
-    {0, 0, 0, 0, {}}};
+    {NULL, 0, 0, 0, {}}};
 
 static const char * block_name[] = {"21140 non-MII", "21140 MII PHY",
                                     "21142 Serial PHY", "21142 MII PHY", "21143 SYM PHY", "21143 reset method"};
@@ -720,7 +720,7 @@ static void parse_eeprom(struct nic *nic)
 
     whereami("parse_eeprom\n");
 
-    tp->mtable = 0;
+    tp->mtable = NULL;
     /* Detect an old-style (SA only) EEPROM layout:
        memcmp(ee_data, ee_data+16, 8). */
     for (i = 0; i < 8; i ++)
diff --git a/src/drivers/net/via-velocity.c b/src/drivers/net/via-velocity.c
index 9ba0b093..e98e81a2 100644
--- a/src/drivers/net/via-velocity.c
+++ b/src/drivers/net/via-velocity.c
@@ -1230,7 +1230,7 @@ static int velocity_open(struct nic *nic, struct pci_device *pci __unused)
 	u32 TxPhyAddr, RxPhyAddr;
 	u32 TxBufPhyAddr, RxBufPhyAddr;
 	vptr->TxDescArrays = tx_ring;
-	if (vptr->TxDescArrays == 0)
+	if (vptr->TxDescArrays == NULL)
 		printf("Allot Error");
 
 	/* Tx Descriptor needs 64 bytes alignment; */
diff --git a/src/hci/linux_args.c b/src/hci/linux_args.c
index 0bce4af9..58eeb063 100644
--- a/src/hci/linux_args.c
+++ b/src/hci/linux_args.c
@@ -45,9 +45,9 @@ __asmcall void save_args(int argc, char **argv)
 
 /** Supported command-line options */
 static struct option options[] = {
-	{"net", 1, 0, 'n'},
-	{"settings", 1, 0, 's'},
-	{0, 0, 0, 0}
+	{"net", 1, NULL, 'n'},
+	{"settings", 1, NULL, 's'},
+	{NULL, 0, NULL, 0}
 };
 
 /**
diff --git a/src/hci/mucurses/kb.c b/src/hci/mucurses/kb.c
index cada7291..b38c8c14 100644
--- a/src/hci/mucurses/kb.c
+++ b/src/hci/mucurses/kb.c
@@ -88,7 +88,7 @@ int wgetnstr ( WINDOW *win, char *str, int n ) {
 	int c;
 
 	if ( n == 0 ) {
-		str = '\0';
+		*str = '\0';
 		return OK;
 	}
 
diff --git a/src/net/udp/dns.c b/src/net/udp/dns.c
index 613541f5..45f0f07c 100644
--- a/src/net/udp/dns.c
+++ b/src/net/udp/dns.c
@@ -205,7 +205,7 @@ static char * dns_qualify_name ( const char *string ) {
 	char *fqdn;
 
 	/* Leave unchanged if already fully-qualified or no local domain */
-	if ( ( ! localdomain ) || ( strchr ( string, '.' ) != 0 ) )
+	if ( ( ! localdomain ) || ( strchr ( string, '.' ) != NULL ) )
 		return strdup ( string );
 
 	/* Append local domain to name */